Rabbi Bechhofer, nowhere does Rav Moshe zt”l state in his teshuvos that he is mocheh regarding the Brooklyn eruvin. On the contrary, he did not even issue a p’sak din barur in opposition to the eruv (Igros Moshe, O.C. 4:87). Additionally, Rav Moshe did not have an issue with the population of Manhattan because it was enclosed with mechitzos. However, he argued that its bridges could be a problem because of the population (since they were not encompassed by mechitzos).

Please, most poskim maintain that we do not include the passengers in vehicles in the tally. The main reason is because they are not holchei regel. I know of two Rishonim who would support this.

Rav Schwab zt”l in the two letters that he penned regarding the Manhattan eruv never made the argument that you mention regarding the need to have the ability to visualize an eruv. In any case, he clearly stated that he hopes that there will come a time when an eruv can be established in all cities. So I guess he changed his mind later with this additional objection. I wonder if he ever objected regarding any other English halachic sefer that was published.

Rav Moshe only mentioned his (Rav Aharon zt”l) chiddush in mefulash later when he wrote his teshuvah about Boro Park. In regards to Manhattan, he stated that he did not understand the criterion of mefulash mechuvanim. (On the contrary, Manhattan according to Rav Moshe’s later chiddush should be fine since its mukaf mechitzos so he would admit that it would need to be mechuvanim as well.)

You have a reading comprehension disorder. I never said that Rav Moshe zt”l, "supported a Brooklyn eruv." I stated that Rav Moshe was not mocheh, and I stand by my statement. Nothing changed from what Rav Moshe told the Flatbush rabbanim and what is written in the teshuvah regarding RMK. Rav Moshe did not issue a p’sak din (barur) when he was asked to by the Flatbush rabbanim as he states clearly in his teshuvah (O.C. 4:87) and so too regarding Boro Park (the typed teshuvah regarding RMK). Clearly, just as he was not mocheh in Flatbush, so too he would not be mocheh in Boro Park.

Moreover, I don’t believe Rav Moshe wrote the teshuva (5:28) as it has been published. There is only a typed copy extent.

Furthermore, Rav Moshe admitted that his objection to these eruvin were based on his own chiddushim so what right do we have to add to these chiddushim? Therefore, there is no reason to argue that Rav Moshe would object to Brooklyn eruvin if they were making use of mechitzos.

Oh, since you’re such an expert on Rav Moshe’s teshuvos, I am sure that you can explain why Rav Moshe allowed an eruv for KGH Queens but not in Brooklyn.

You stated: "He did not even issue a p’sak din barur in opposition to the eruv."

That's not true. He stated clearly that he held that one who carries in Brooklyn is michalel Shabbos. In his tzidkus, he told people not to be mocheh on those who felt they knew better than the posek hador.

Apparently, Reb Moshe Zt"l would have told the masses not to be mocheh against you for violating his psak.

That must make you feel more confident as a bar plugta with Reb Moshe.

Lineman:

"Moreover, I don’t believe Rav Moshe wrote the teshuva (5:28) as it has been published. There is only a typed copy extent."

That's not true. The original ksav yad is available.

Lineman:

"Furthermore, Rav Moshe admitted that his objection to these eruvin were based on his own chiddushim so what right do we have to add to these chiddushim? Therefore, there is no reason to argue that Rav Moshe would object to Brooklyn eruvin if they were making use of mechitzos."

That's not true. As stated Reb Moshe was clear that he held it is not possible to establish an eruv in Brooklyn.

Lineman:

"Oh, since you’re such an expert on Rav Moshe’s teshuvos, I am sure that you can explain why Rav Moshe allowed an eruv for KGH Queens but not in Brooklyn."

You should stick to this mhalach. Instead of making up baseless foolish answers, you remain with a good question.

Rabbi Bechhofer, please explain to me what happened between the time Rav Moshe wrote to the rabbanim of Flatbush that he can’t issue a p’sak din barur because the Achronim and the Aruch HaShulchan would not agree with him and this so called hashmatah. All of a sudden, Rav Moshe maintained that one should be mocheh even though those supporting the eruv have on whom to rely -- the Achronim and the Aruch HaShulchan? Please, this hashmatah makes no sense. Moreover, maybe 4:87 was written after this hashmatah since this Addendum is not dated; hence Rav Moshe changed his mind and one can’t be mocheh. In any case, there is no difference between Manhattan and Brooklyn today since Brooklyn is also encompassed by mechitzos.

Lineman, you made four statements- all of which were false (when I pointed them out, you didn't even argue).

You want to carry in Brooklyn or Manhattan? Just understand that according to Reb Moshe Zt"l you are being michalel Shabbos. Period.

You are not living in reality if you think you understand the Eruv in Brooklyn better than the Posek Hador Ztl, who reviewed all the raw data/population figures. He said that an eruv could not be established in Brooklyn.

You want to rely on your "mechitzos"? You have to find another Posek to be somech on.

Or you could claim to understand Reb Moshe's psakim better than his own kisvei yad, and any talmid chacham that learned by him.